[Rebecca Solnit is the author of "Hope in the Dark: Untold Histories, Wild Possibilities" and "River of Shadows: Eadweard Muybridge and the Technological Wild West."]

The place where the teenage twins were murdered was beautiful, and the men who killed them and their uncle were to become among the most celebrated in the United States. But on that Sunday, June 28, 1846 -- 160 years ago -- the murder site just north of San Francisco was not in the United States. It, like the rest of California and the entire Southwest, was still Mexico, and this is why the two de Haro boys, Francisco and Ramon, were shot down in cold blood with their elderly uncle, Jose de la Reyes Berryessa.

The picture is clear to me, the three men standing up against the blue water of San Pedro Bay, wearing serapes, carrying saddles, startled, then stunned, then dead, one by one, as the gunman picked them off. There's something about those three figures against the water of the pristine bay, stark and symbolic. Blue water. Gold hills. Three upright against the beauty of the place. Then three bodies lying crumpled on the shore. It's the kind of death sung about in ballads, the kind of death that paintings are made of. No one has made much of this one, though San Rafael-born poet Robert Hass mentioned their deaths in the poem "Palo Alto: The Marshes" 30 years ago.

Some accounts put the murder scene at Point San Pedro, the semi-rustic peninsula jutting into the bay, some closer to Mission San Rafael in what is now the town center. All the accounts agree that the three Mexican citizens had rowed across from Point San Pablo north of present-day Berkeley, though whether they knew that the Bear Flag Revolt had begun a few weeks earlier is disputed. News in those days traveled at the speed of a horseman or a boat, and news of the seizure of Northern California's administrator, Mariano Vallejo, in Sonoma on June 14 may not have reached many of his fellow Californios -- as the Mexican citizens of Alta, or upper, California were called.

The little war had been brewing for a while. President James Polk had major territorial ambition, and he had sent emissary Thomas Larkin to encourage the Californios to defect with their territory to the United States. At the same time, he had pushed Great Britain to settle the dispute over the Pacific Northwest and acquired what is now Oregon and Washington for the United States, as well as annexing the newly independent (from Mexico) Texas and starting what our school textbooks called the Mexican-American war. It might more accurately be called the war on Mexico, because we started it. When it was done, Mexico unwillingly ceded about half its territory -- 1.2 million square miles including New Mexico, part of Colorado, Arizona, much of Utah, Nevada and California.

Huge swaths of land -- which really belonged to the nations that had been there long before Spain, Mexico or Polk -- transferred title in those years and the United States assumed its modern coast-to-coast shape. But the Bear Flag Revolt wasn't epic or heroic, just a strange squabble that melded into the Mexican-American war. It began when a number of Yankee settlers near Sutter Buttes in the Central Valley, inflamed by rumors that a small army of Mexicans was coming to drive out the illegal aliens -- the Americans -- decided to jump the gun and seize the place. They set out in the second week of June, recruiting as they went, so that about 30 of them stole into Sonoma's plaza at dawn on the 14th.

There, the illegal aliens stormed Vallejo's home and took him hostage. Some wore buckskin pants, some coyote-fur hats, some had no shoes. One account describes them as "a marauding band of horse thieves, trappers and runaway sailors." Vallejo was a man of culture, a rancher and a reluctant governor, not averse to being annexed by the United States but not inclined to become a prisoner or a second-class citizen. It was his open immigration policy that had created the problem in the first place. They raised a flag with a bear so badly drawn that some of the Mexicans thought it was a pig; a better version of it is still the California flag, though the grizzly on it became extinct 84 years ago. The ironies pile high.

Capt. John Charles Fremont, who had entered California illegally with a band of scouts and soldiers, egged on the revolt and then joined it, stealing horses, commandeering supplies and pretty much doing anything he liked. That morning of June 28, he and his chief scout Kit Carson were near the shores of San Rafael when the de Haro twins rowed their uncle across so that he could, by some accounts, visit his son in Sonoma. Carson asked Fremont what to do about these unarmed Californios.

Fremont waved his hand and said, "I have got no room for prisoners." So Carson, from 50 yards away, shot them. As one history relates it, "Ramon was killed as soon as he reached the shore. Francisco then threw himself on his brother's body. Next, a command rang out: 'Kill the other son of a bitch!' It was obeyed immediately." When the uncle asked why the boys had been killed, he was shot down, too. Berryessa's son Antonio ran into a Yankee wearing his father's serape -- the bodies had been stripped of their clothing and left where they lay -- and asked Fremont to order its return to him. Fremont refused, so Berryessa paid the thief $25 for the garment.

The son remained bitter for the rest of his days. The father of the twins is said to have died of grief. California became part of the United States. Carson shot more people in cold blood soon afterward, near what is now Las Vegas. Later he became a popular frontier hero, the subject of many laudatory and partly fictitious books. Fremont's star rose. He became the 1856 presidential candidate for the new Republican Party. He ran on an antislavery platform, but old scandals, including commanding the murder of Berryessa and the de Haros, surfaced. San Francisco surveyor Jasper O'Farrell testified against him in the only first-hand account of the murder, and Fremont failed to carry the state of California. Several more Berryessa men were murdered by Yankees after the war, and the family lost its vast holdings of Bay Area land.

There are far more deaths that history neglects to mention, including the deaths of those crossing the line drawn in the sand after the Mexican-American war. It's all a reminder of the arbitrariness of borders and the color of justice.

But the picture remains of those three men on the shores of San Rafael. I grew up one town over, told that history had happened elsewhere, back in those days when everything before the Gold Rush was glossed over. I wish that someone would put up a monument to these three victims, maybe as statues on the shore or maybe as a mural in what is now the barrio in that town, the Canal District near what may have been the murder site. Or in the center of the city, on Fourth Street, whose only claim to fame now is that some of the cruising scenes of George Lucas' "American Graffiti" were shot there.

Much happened in California 160 years ago, and it has everything to do with what is happening now on the border created then and with the status of Latinos who are often treated as invaders, even when for many of them the story is, "We didn't cross the border; the border crossed us."

There is another monument of a sort to all these characters. Fremont and Vallejo are streets that never quite cross in the northeast of San Francisco. Larkin and O'Farrell streets run farther west, intersecting in the Tenderloin. De Haro Street runs across Potrero Hill, farther south in the city, named after relatives of the murdered twins. Berryessa is a man-made lake that arrived on the scene much later. Carson is a pass in the Sierra Nevada, a suburb in Los Angeles, a public school in Las Vegas and a monument in Santa Fe, while his commander is a city in the East Bay and the South Central Los Angeles high school my father graduated from. But these don't tell the story to those who don't already know the strange, bloody way California entered the United States.